Air cleaner



April 21, 1 G. E. LUNDBERGY ET Al. 2,280,417

AIR CLEANER Filed March 18, 1940 175067920725 wiwalzwwi e2 Patented Apr. 21, 1942 AIR CLEANER Gustave E. Lundberg and Arthur R. Crawford,

Riverside, Ill., ,assignors to International Barvester Company, a corporation of New Jersey Application March 18, 1940, Serial No. 324,584

9 Claims.

This invention relates to an air cleaner. More specifically, it relates to an air cleaner in which the air is brought into contact with liquid.

In the use of air cleaners for engines, it has been found necessary to use a liquidwetted surface and to intimately contact and re-contact the air with diiierent portions of the surface in order to obtain the necessary effectiveness in removing the fine particles. In cleaners of this type the air is usually mixed with the liquid prior to its contact with a filter medium. In designing a satisfactory cleaner, it is necessary to provide means for mixing a suitable amount of liquid with the air and to provide means for separating the liquid from the air stream and returning it back to additional incoming air. The principal object of the present invention is to provide an improved air cleaner of the liquid or oil bath type in which provision is made for continually returning a portion of the liquid back into the incoming air stream.

Another object is to provide a baflie structure in a: cleaner of the oil bath type in which oil is introduced into the air stream annularly around the air intake. a

Another object is to, provide separate means, one fed by drainage from the filter element and the other by pressure from the oil reservoir, for delivering oil at two pointsinto the air stream for obtaining a more uniform distribution. The above objects and others relating to structural details will be apparent from the description to follow. I

In the drawing,

Figure 1 is a side elevation of an air cleaner embodying the invention with a lower portion broken away on a vertical section through the center of the cleaner, and an upper portion brokfor connection to a hose, or other conduit means, leading to the carburetor intake. An oil reservoir cup I3 is slidably fitted over the bottom of the casing l and has a bead I! at the upper end which fits against an outwardly extending flange on the casing. Said cup'is held in position by two threaded securing elements 2| having heads seated on a flanged band 22 encircling the casing ll above the flange 2!. Thumb nuts 23 on the elements 2| abut the lower side of a cross member 24 secured to the bottom of the cup ll. An outwardly extending bead 25 is formed in the cup l8 to indicate the normal liquid level in the cup. It will be noted that the bottom of the inlet tube l6 extends somewhat below the normal static liquid level in the cup.

A plurality of conical bailles 25 is positioned in the filter compartment l5. Said ballles, as illustrated, slope downwardly from the center tube to the outer wall of the casing and are provided with flanges 21 abutting the tube I6 and flanges 2B abutting the casing wall. A plurality of radially extending slits 2.9 formed in the baflles in staggered relation in the successive baflles proen away on the same section to show the internal construction;

Figure 2 is a section taken on the line 2-2 of Figure 1; y I

Figure 3 is a section taken on the line 3-3 of Figure 2,

The drawing illustrates a cleaner of a type widely used for tractor engines. A cylindrical casing l0, open at its bottom end, is provided at its upper end with a closure including a cover member H and a bottom plate member I2. bottom plate member has a recessed shoulder l3 which fits around the top of the cylindrical casing II]. A plurality of openings I4, one of which is shown, provides an outlet for filtered air from an annular filtering compartment l5 formedbetween the wall of the casing-Ill and an inlet tube l6. Said tube extends vertically through an opening in the top of the cover member Hand through an opening in the plate member l2 terminating slightly below the bottom of the casing H). An outlet tube H is formed on the plate I2 casing consists essentially of a partition wall in 1 .the form of a baffle cup33 and a baflle member The C vides a tortuous passage through the bailles. A plurality of relatively fine mesh screens 30 is also shown located between adjacent baffles. Upturned walls are provided adjacent the slits 29 to provide oil-return channels therebetween whereby the oil as it is separated out of the air stream returns downwardly toward the other wall of the casing. Staggered openings 32 are provided in alternate baflles 'to return the collected oil to the lower portion of the casing. The structure of these batlles is covered by United States Patent 2,199,019, April 30, 1940 and is shown in this application only in' so far as is necessary to provide a baffle for the adequate. disclosure of the improved baffle construction.

The baflle construction at the bottom of the 34 providing liquid and air conditioning means. Said baffle member is generally conical in shape with the cone extending in a direction opposite the baffles 28; that is, downwardly over the inlet tube l6. Adjacent the inlet tube, said bath: is formed with a downwardly extending wall 35, cy-

' lindrical in shape and of a larger diameter than the inlet tube It, to provide an annular oil-return space 36 between the wall 35 and the tube It. To provide means for securing the baffle member 34 to the inlet tube IS, a plurality of indented portions 31, formed from the wall 35, abut the tube It and are secured thereto by soldering or by other suitable means. It will be noted that the wall 35 terminates a distance above the lower extremity of the tube It approximately equal to the radial thickness of the annular oil-return passage 36. An outwardly turned flange 38 formed at the lower end of the tube It cooperates with the wall 35 to form an oil discharge for the passage 36 which is in a relatively low pressure zone of the filter. This results from a Venturi or ejector action resulting from the inlet air rushing over the curved flange or lip 38. The upper and outer portion of the baflle member 34 is provided with a horizontal portion 39 to which a horizon-.

tal flange 40 on the bafile cup 33 is secured. It will be noted that the flanges 39 and 40 terminate a substantial radial distance from the wall of the casing 50, thereby allowing adequate space for oil return to the reservoir provided by the cup l8. I

The baffle cup 33 has a substantial vertical liquid retaining wall portion joining the flange 40 and a downwardly and centrally sloping conical bottom portion M terminating in a flat bottom portion 42 in which an oil supply aperture 43 is formed, said vertical wall portion provides a space for air flow between the wall portion and the inlet tube, and a liquid compartment between the wall portion and the wall of the casing.

To provide for air flow through the bafile member 36 and for oil flow thereover, a plurality of I openings 44 are formed surrounded by upstanding walls 45. The walls 45 are continuous around the openings 44 and vary in height, being higher on the outside than toward the center adjacent the inlet tube it. This particular shape acts both to prevent overflow of oil damming up at the outside of the casing from flowing over the walls into the air streams passing through the openings M and also to direct the air stream to the center part of the filtering compartment l adjacent the center tube It.

The walls 45 also provide channels 46 therebetween ofa substantial width and depth through which oil may flow from the outside of the casing to the center thereof.

In the operation of the air cleaner as above described, the cup I8 is filled before the begin-- ning of operation to a static level indicated by the bead 25. The air passing inwardly through the inlet tube It carries a substantial portion of the oil in the bafiie cup 33 upwardly into the filter where it is intimately mixed with the air. As the oil is separated at higher points in the filter compartment, it runs downwardly toward the wall of the casing it] and flows back through i the drain openings 32 to the reservoir. The incoming air carries the oil out of the bafiie cup 33 during capacity operation much faster than it is returned through the restricted opening 63. It will be understood'that the oil displaced from the cup builds up outside the cup between the batile structure and the casing. As the level of oil rises, it eventually becomes higher than the horizontal flange, 39 of the baffle member 34. At that point the oil drains across the bafiie member 34, passing inwardly and downwardly through the channels 46 and back into the air stream through the channel or passage 36. Due to the location of the flange 38 on the tube I6 and the wall 35, there is never sufiicient pressure differential between the two sides of the bafile 34 to prevent the flow of returned oil downwardly through the passage 36 into the air stream. This passage is ofsuch a size that all of the excess oil built up above the horizontal level of the flange 39 is continually returned and recirculated. It will be understood that a portion of the oil is at all times held in the filtering compartment, an equilibrium condition being obtained at any rate of air flow through the cleaner.

During operation as above described, oil from the cup I8 is being delivered continuously through the opening 43 into the incoming stream of air. A portion of the oil returned from the filtering compartment is also being continually added to the air stream through the passage 36. By a dual supply of fluid in this manner, requirements for thorough wetting of the air upon its engagement with the filter element are assured. The provision of the drain channels in the baffie structure allow the oil to return and prevents the accumulation of an undesirable amount of oil in the filter element.

In accordance with the operation above described in detail, applicants have produced an improved oil filter which functions to obtain an improved result with a balanced condition of air and oil flow. It is understood that the showing illustrates only a preferred form of the invention and that applicants claim all modifications falling within the scope of the appended claims.

What is claimed is 1. In an air cleaner having a casing, a central air inlet tube and an oil cup at the bottom of the casing in spaced relation with respect to the inlet tube, and, in combination therewith, a baffle structure at the bottom of the casing including a baflle member extending radially outwardly and upwardly from adjacent the bottom of the inlet tube, said baffle being formed with a plurality of openings forming air flow passages and with channels therebetween for the flow of oil toward the tube and oil drain means adjacent the air inlet tube delivering the oil directly into the air stream outside and at the bottom of the tube.

2. In an air cleaner having a casing, a central air inlet tube and an oil cup at the bottom of the casing in spaced relation with respect to the inlet tube, and, in combination therewith, a bafile structure at the bottom of the casing including a conical ballie member connected to the bottom of the inlet tube at spaced locations and spaced therefrom to provide passages for the flow of oil downwardly adjacent and outside the inlet tube into the air stream passing between the inlet tube and oil cup, said baflle having a plurality of up-struck wall {portions forming channels therebetween for the flow of oil toward aforesaid passages between the inlet tube and the baffle member, and a bafiie cup secured to the baffle. said baffle cup being provided with an oil inlet opening.

3. In an air cleaner having a casing, a central air inlet tube and an oil cup at the bottom of the casing in spaced relation with respect to the inlet tube, and, in combination therewith, a baffle structure at the bottom of the casing including a bafile member extending radially outwardly and upwardly from the bottom of the inlet tube, said bafile being provided with a plurality of up-struck wall portions forming air flow passages and channels therebetween for the flow of oil and with a depending flange spaced from the inlet tube to form an oil return passage, said inlet tube being flared outwardly below said flange to form a low pressure area for the return of oil.

4. In a liquid type air cleaner having a casing including a liquid reservoir at its bottom, a central air inlet tube terminating above the reservoir and contact material, in the space between the tube and the casing, and in combination therewith, a cup surrounding the bottom of the inlet tube in spaced relation thereto and having an upwardly'extending wall space-d from the air inlet tube thereby providing an annular passage for incoming air, said upwardly extending provide for flow of liquid therebetween from the reservoir, a baflie structure arranged at the upper part of said upwardly extending wall and sloping downwardly toward the lower end of the inlet tube, said structure being provided with-openings and with upwardly extending walls entirely surrounding said openings thereby preventing any fiow of liquid into the air stream passing through 'wall being also spaced from the casing wall' to the openings, said walls also providing channels around and between the openings for the flow of liquid inwardly toward the inlet tube from the an upwardly extending wall spaced from the air inlet tube thereby providing an annular passage for incoming air, said upwardly extending wall being also spaced from the casing wall to provide tor flow of liquid the-rebetween from the reservoir, a baffle structure arranged at the upper part of said upwardly extending wall and sloping downwardly toward the lower end of the inlet tube, said structure being provided with openings and with upwardly extending walls entirely surrounding said openings thereby preventing any flow of liquid into the air stream passing through the openings, said walls also providing channels around and between the openings for the new of liquid inwardly toward the inlet tube from the liquid passage between the casingand the cup wall, the lower edge of the baille structure being spaced from the inlet tube to provide a passage for the downward flow of liquid therebetween directly into the incoming air stream, and means for admitting liquid at the bottom or said cup.

6. In a liquid air cleaner having a casing and a central air inlettube terminating above the bottom of the casing, and in combination there- '7. A liquid type air cleanercomp'rising' a cylindrical casing having a liquid reservoir at its bottom and a filter element at its top, a vertical air inlet tube disposed axially of the casing and having its lower end spaced above the bottom of the liquid reservoir, a bafile cup interposed between the lower endof the tube and the reservoir and having a circular, substantially vertical wall concentrically spaced between the tube and casing, said wall having an upper edge portion disposed generally at a height above' the lower end of the tube, the space between the tube and cup providing an air passage for an air stream upwardly through the filter element and the space between the cup and casing providing a liquid passage for the flow of liquid from the reservoir over the edge of the bafile cup wall, and

means cross connecting the tube and the'upper ends'of the well of the baille cup for conveying liquid from the aforesaid edge of the baiile cup, across the air passage and separate from the aforesaid air stream, to the lower end of the inlet tube.

8. A liquid type air'cleaner comprising a casing having an outer wall and a liquid reservoir adapted to contain liquid, an air inlet tube in i the casing having its lower end spaced above the reservoir, a filter element between the casing and the upper portion of the tube, the normal air stream passing through the tube and around the lower end of the tube and upwardly through the filter element, means in the filter for conveying at least a portion of the entrained liquid toward the outer wall of the casing for draining said liquid to the reservoir, a partition elementin the reservoir separating the lower end of the tube from the main body of liquid and having a restricted liquid inlet to restrict the flow of liquid to the incoming air, said partition element including an upper portion extending between the outer wall of the casing and the inlet tube to a with, conical liquid intercepting baliles located in 1 the space between the inlet tube and the casing wall, said baflles sloping downwardly toward the casing wall and being provided with openings and liquid conducting channels for carrying liquid to the casing wall and downwardly along said wall, a cup surrounding the bottom of the inlet tube in spaced relation thereto and having an upwardly extending wall spaced from the air inlet tube thereby providing an annular passage for incoming air, said upwardly extending'wall being also spaced from the casing wall, a baille structure arranged at the upper part or said upwardly extending wall and extending downwardly toward the lower end of the inlet tube, said baille being provided with openings and with liquid conducting channels between the openings for the flow or liquid from the casing wall inwardly toward the inlet tube, and means at the lower end or the baflle structure to provide a passage for the downward flow of liquid directly into the incoming air stream.

height above the lower end or the tube and above the normal liquid level whereby the liquid level is raised as liquid drains from the aforesaid means in the filter element and as pressure increases on the portion of liquid exposed to incoming air, and means extending inwardly from the upper portion of the separating element to the inlet tube for conveying liquid to the lower end of said tube whence itdrains off the end or the tube into the air stream, said means also providing passages for the upward flow of .air out of contact with the liquid.

9. A liquid type air cleaner comprising a cylindrical casing having a liquid reservoir at its bottom, avertieal air inlet tube disposed axially of the casing with its lower end spaced above the bottom of the liquid reservoir, a vertical liquid retaining wall interposed between the lower end of the tube and the reservoir with its upper portube, the space between the tube and the wall providing for an air stream upwardly to the filter element and the space between the wall and the casing providing a liquid compartment, and means extending inwardly from the upper portionof said liquid retaining wall to the lower end of the inlet tube for conveying liquid from the liquid compartment formed by the retaining wall to the inlet tube, said means also providing passages for the upward flow of air out of contact with the liquid. Q

' .GUSTAVE 'E. LUNDBERG.

ARTHUR R. CRAWFORD. 

